Changes of neutrophil elastase and alpha 1-antitrypsin in systemic lupus erythematosus.

Contents of HNE and alpha 1-AT and the positive rates of PMN-Ab in patients with SLE were measured and tested by ELISA, immunodiffusion and protein-A rosette, respectively, and it was found that plasma HNE content was significantly higher in patients with SLE (61.0 +/- 13.9 ng/ml) than in normal controls (33.7 +/- 6.7 ng/ml, P less than 0.001), while plasma alpha 1-AT in patients with SLE (2.79 +/- 0.47 mg/ml) was similar to that in normal controls (2.55 +/- 0.38 mg/ml, P greater than 0.6). The positive rate of PMN-Ab in SLE (9.8 +/- 6.5) was also significantly higher than that in normal (0.17 +/- 0.2%, P less than 0.001). The results suggest that there is an imbalance between plasma HNE and alpha 1-AT in SLE regardless of WBC or the positive rate of PMN-Ab, with this imbalance probably being due to activation of neutrophils following multiorgan damage of SLE.